Пятница, 8 января 2016, 10:14 +01:00 от Clemens Ladisch <cladisch@xxxxxxxxxxxxxx>:
Sergei Steshenko wrote:
> Понедельник, 4 января 2016, 18:45 +01:00 от Clemens Ladisch <cladisch@xxxxxxxxxxxxxx>:
>
> Sergei Steshenko wrote:
> > I have developed a piece of code (as LADSPA plugin) which among other things multiplexes one of two input streams into output stream.
> >
> > Though switching worked, latency was several seconds long instead fraction of a second.
> >
> > Because of the latency I suspected a problem with my code, but after creating a special test audio files I've established that the multiplexing happens fast - within my LADSPA host buffer length, as expected. And the buffer length was 1024 samples @44100KHz.
>
> What is the buffer length of the device?
> (see /proc/asound/card*/pcm0p/sub0/hw_params)
>
> "buffer_size: 262144", and 262144/48000 is about 5.46 seconds - feels about right.
The audio device is configured by whatever program actually writes to it,
probably your host. What is it? How is it configured?
Regards,
Clemens
"The audio device is configured by whatever program actually writes to it" - the program is 'ecasound'. But the point is the buffer length is different for USB and non-USB cards.
For example, at the moment I am using "M-Audio Revolution 7.1", and for it I see:
"
sergei@amdam2:~/tmp> cat /proc/asound/card1/id
Revolution71
sergei@amdam2:~/tmp> cat /proc/asound/card1/pcm0p/sub0/hw_params
access: MMAP_INTERLEAVED
format: S32_LE
subformat: STD
channels: 2
rate: 44100 (44100/1)
period_size: 1024
buffer_size: 32768
".
Again, it's the same 'ecasound' with my audio stuff as LADSPA plugin for it. I.e. the code I wrote has no access to audio device.
For that matter, for on board "Nvidia", with a Youtube video playing through Firefox:
"at /proc/asound/card0/pcm0p/sub0/hw_params
access: MMAP_INTERLEAVED
format: S16_LE
subformat: STD
channels: 2
rate: 44100 (44100/1)
period_size: 44096
buffer_size: 88192
".
Regards,
Sergei.
------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140
_______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
